Circuit arrangement with door lock switch

ABSTRACT

A door lock switch installation in which the door lock switch is connected, via the door hinge, to an impulse relay connected in series with the load, for example a lamp for illumination of the room closed by the door. When the door lock is actuated in a predetermined manner, the switch is momentarily closed to deliver a pulse to the impulse relay which then makes or breaks the load circuit.

United States Patent [1 1 Kellermeyer CIRCUIT ARRANGEMENT WITH DOOR LOCK SWITCH [76] Inventor: Christian Kellermeyer, Valtinstr. 6,

D-8858 Neuburg, Germany [22] Filed: Sept. 10, 1971 [21] Appl. No.: 179,426

[30] Foreign Application Priority Data Sept. 15, 1970 Germany P 20 45 527.0

[52] US. Cl. 307/116, 339/4 [51] Int. Cl. H01h 35/00 [58] Field of Search ZOO/61.47; 339/4;

[56] References Cited 7 UNITED STATES PATENTS 1,744,040 Elzer 339/4 June 19, 1973 FOREIGN PATENTS OR APPLICATIONS 1,132,635 9/1955 France 339/4 Primary Examiner-Herman J. Hohauser Att0rneyBruce & McCoy [57] ABSTRACT A door lock switch installation in which the door lock switch is connected, via the door hinge, to an impulse relay connected in series with the load, for example a lamp for illumination of the room closed by the door. When the door lock is actuated in a predetermined manner, the switch is momentarily closed to deliver a pulse to the impulse relay which then makes or breaks the load circuit.

3 Claims, 3 Drawing Figures Patented June 19, 1973 IN VEN TOR BY cnmsmu KELLERMEYER QM g-gt' w CIRCUIT ARRANGEMENT WITH DOOR LOCK SWITCH BACKGROUND OF THE INVENTION The invention relates to a circuit arrangement for switching on and off current utilizing devices or loads by means of an impulse relay disposed in the lead to the load. Such circuit arrangements are known; they are known also for residential installations, and they are advantageous in that the line carrying the operating voltage need extend only from the junction box to the load, of course, via the impulse relay, whereas only a relatively inexpensive line for low voltage is needed to that point at which the switch is to be located. Furthermore, it is advantageous that it is possible to switch the same load on and offfrom any desired number of locations.

Furthermore, door contact switches are known comprising, in general, a push button switch mounted in the door frame and being pressed down sufficiently, when the door is closed, to keep the switch open and moving forward, upon opening of the door, so far as to cause I the switch to be closed and current to be supplied to the load. Such switches are used above all for switching on and off means for illuminating the interior of closed spaces, most well-known examples of which are motor vehicles and refrigerators. Such door contact switches suffer particularly from the disadvantage that the full voltage and, above all, the full current of the load must flow through the switch. For this reason the door contact switches in question could be introduced only for use in special cases, namely where relatively low-power loads are operated at low voltages. It is not possible to replace such adoor contact switch'bya door contact and'an impulse relay because a door contact switch closes as the door is opened and opens again as the door is closed and thus cannot send current impulses to the exciter winding of the impulse relay.

It is, therefore, the object of the invention to provide a circuit arrangement of the kind mentioned initially, i.e., including an impulse relay, designed such that an impulse is supplied to the exciter winding of the impulse relay each time a door is opened and/or closed. This is achieved in accordance with the invention by an arrangement in which the exciter winding of the impulse relay is connected with a switch, disposed in the door lock, 'by way of the door hinges and hinge pins, which switch is closed when the door handle is in a certain position and is open otherwise.

With such an arrangement a current impulse is given each time the doorhandle is actuated. This is desired in many cases where the load is to be switched on and off automatically upon opening or closing of the door, as is the case, for instance, with the light in a refrigerator.

In other cases, however, it is desired to supply a current impulse to the exciter winding of the impulse relay only upon opening and/or closing of the door, and particularly only when desired. This may be achieved in accordance with a special aspect of the invention by providing the shaft of the lock with an additional cam directed upwardly and, upon movement of the door handle contrary to the normal direction of opening, closing the switch, and by having the door handle retained in its rest position by an abutment spring the force of which, relative to the shaft of the lock, is greater than that of the normal retraction spring. With this embodiment of the invention a current impulse is given each time the handle of the door is moved in contrast to its normal direction of opening so that the load may be switched on or offjust as desired, either in connection with the opening and closing of the door or independently.

With the usual Iow voltages needed to excite impulse relays the contact resistance between the door hinges and the hinge pins plays an important part. If too high a contact resistance must be expected, a special embodiment of the invention provides for lubricating the hinge pins with graphitized fat which, being conductive, reduces the contact resistance to a small amount.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which FIG. 1 is an elevational view of a door prepared for a circuit arrangement embodying the invention;

FIG. 2 is an elevational view of a door frame for the door shown in FIG. 1;

FIG. 3 is a diagrammatic view of the lock of the door shown in FIG. 1.

Two electrical lines 11 and 12, as shown schematically in FIG. 1, lead from the door lock to two door hinges 14 and 15.

As shown in FIG. 2 two further lines 11' and 12' lead from the hinge pins 16 and 17 at the door frame 18 to a conventional junction box (not shown) which may be mounted, for instance, in the hall if the door shown in FIG. 1 is a door leading into a housing, an apartment, or a room. An impulse relay is housed in a manner known per se in the junction box and is connected in the lead to an electrical load, for example the lead to the illumination means of the hall or room. Moreover, a transformer is provided for step-down transforming of the main voltage to the supply voltage of the exciter winding of the impulse relay, and the lines leading to the exciter winding are connected in the junction box with the lines 11' and 12 from the hinge pins 16 and 17.

As soon as the door shown in FIG. 1 has been hung in the frame 18 shown in FIG. 2, i.e., when the door hinges 14 and 15 will have engaged the pins 16 and 17, respectively, a current impulse can be supplied to the exciter winding of the impulse relay as soon as a switch 19, shown symbolically, in the door lock 13 and connected to the two lines 11 and 12 will be closed briefly.

As usual, the lock 13 shown in detail in FIG. 3 comprises a shaft 20 provided with a square hole 21 to receive the handle axis, a bolt 22, a cam 23 to operate the bolt, and a retraction spring 24.

Additionally, the lock shown in FIG. 3 includes a cam 25 to operate the switch 19, already mentioned, which is connected to lines 11 and 12 of the door shown in FIG. 1.

Instead of the customary abutment member determining the rest position of the shaft of the lock and thus of the door handle an abutment spring 26 is provided the force of which, acting on the shaft 20, is greater than the force of the retraction spring 24 so that the spring 26 presents a stop or abutment for the spring 24 to be overcome, however, by an appropriate force exerted on the door handle.

To open the door lock the shaft 20 is rotated by means of the handle in the usual way in the direction of arrow 27, whereupon a spring (not shown) retracts the cam 22 from the position shown into a retracted position so that the door may be opened or closed. This mode of operation is known. There are certain differences for other lock designs, yet they are insignificant for the present invention.

If the handle is moved upwardly so as to move the shaft in the direction of arrow 28, i.e. counterclockwise as seen in FIG. 3, overcoming the force exerted by abutment spring 26, the switch cam will contact switch 19 briefly closing the same and thus supplying an impulse to the exciter winding of the impulse relay which will break or make the circuit to the load.

It is obvious that the cam operating the switch and the switch itself may also be arranged differently within the scope of the invention, if desired, so as to obtain different combinations of the movement of the door handle and of the current impulse fed to the relay.

What I claim is:

1. ln acircuit arrangement for switching on and off loads by means of a door handle mounted on a door suspended in a door frame by door hinges and hinge pins, the improvement comprising an impulse relay provided in the lead to the load, the exciter winding of the relay being connected with a switch arranged in the door lock by way of the door hinges and hinge pins, .said switch being closed with the door handle in a, certain position and otherwise being-biased open.

2. A circuit arrangement as claimed in claim 1, in which the shaft of the door lock is operated by a retraction spring and carries and additional cam secured to the shaft of the door lock, said door handle being retained in its rest position by an abutment spring which bears against said cam and the force of which is greater than that of the retraction spring whereby the abutment spring biases the door lock to keep the switch open, said switch being closed by movement of the door handle contrary to the normal direction of opening.

3. A circuit arrangement as claimed in claim 1 in which the hinge pins are lubricated with graphitized grease. 

1. In a circuit arrangement for switching on and off loads by means of a door handle mounted on a door suspended in a door frame by door hinges and hinge pins, the improvement comprising an impulse relay provided in the lead to the load, the exciter winding of the relay being connected with a switch arranged in the door lock by way of the door hinges and hinge pins, said switch being closed with the door handle in a certain position and otherwise being biased open.
 2. A circuit arrangement as claimed in claim 1, in which the shaft of the door lock is operated by a retraction spring and carries and additional cam secured to the shaft of the door lock, said door handle being retained in its rest position by an abutment spring which bears against said cam and the force of which is greater than that of the retraction spring whereby the abutment spring biases the door lock to keep the switch open, said switch being closed by movement of the door handle contrary to the normal direction of opening.
 3. A circuit arrangement as claimed in claim 1 in which the hinge pins are lubricated with graphitized grease. 